Heart valve delivery system with valve catheter

ABSTRACT

An assembly for treating a native valve in a human heart includes a prosthetic heart valve having an expandable frame and a valvular structure. The assembly also includes a tubular sleeve and a valve catheter disposed within the sleeve. A plurality of metal extension arms are coupled to the valve catheter for holding the prosthetic heart valve. The extension arms are configured to radially expand with the prosthetic heart valve during expansion of the prosthetic heart valve at a treatment site. A plurality of metal rods extend distally from the valve catheter. The rods are axially movable relative to the extension arms. A plurality of release members are provided for releasing the prosthetic heart valve from the extension arms upon movement of the metal rods.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/347,505, filed Nov. 9, 2016, now U.S. Pat. No. 9,839,514, which is acontinuation of U.S. application Ser. No. 14/561,113, filed Dec. 4,2014, now U.S. Pat. No. 9,539,092, which is a continuation of U.S.application Ser. No. 13/449,200, filed Apr. 17, 2012, now abandoned,which is a continuation of U.S. application Ser. No. 11/252,657, filedOct. 18, 2005, now U.S. Pat. No. 8,167,932, the entire disclosures ofwhich are incorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to systems used to delivermedical implants into a human body. More particularly, the presentinvention is directed to a delivery system for delivering a prostheticvalve to a human heart.

BACKGROUND

Catheter-based procedures are commonly used in medical practice to treatregions within the body that are not easily accessible by surgery orwherein access without surgery is desirable. In one catheter-basedprocedure, a prosthetic valve is delivered to a human heart using apercutaneous approach for replacing a defective native heart valve.Although the replacement of native heart valves using percutaneouslydelivered prosthetic valves has shown great potential, the effectivenessof this procedure is often limited by the operator's ability to navigatethrough the patient's vasculature, such as through small vessels andaround the aortic arch.

In one delivery method, a prosthetic valve is mounted on a ballooncatheter. Before advancing the prosthetic valve to the heart, a guidesheath is introduced into the iliac artery of the patient. Although theguide sheath adds diameter and complexity to the system, the guidesheath is necessary for advancing the catheter and prosthetic valvethrough the relatively narrow arterial vessels. The balloon catheter andprosthetic valve are pushed by the operator through the guide sheath tothe treatment site. In one shortcoming of this procedure, the ballooncatheter may lack the pushability required to be effectively advancedthrough the guide sheath. Furthermore, after exiting the guide sheath,the prosthetic valve may come into contact with the inner wall of thevessel, such as along the aortic arch. As a result of this contact, thevessel wall may be damaged and advancement of the prosthetic valve maybe impeded or prevented altogether. Furthermore, calcification andplaque can be dislodged from the vessel wall.

Due to the shortcomings associated with existing delivery systems, thereis a need for a new and improved delivery system that may be used todeliver a prosthetic valve to a human heart in a safe and effectivemanner. It is desirable that such a system does not require the use of aconventional guide sheath. It is also desirable that such a system easesthe tracking process and reduces the displacement of plaque orcalcification along the inner walls of the body vessels. It is alsodesirable that such a system has sufficient flexibility to track throughthe curves of a body vessel, while providing sufficient pushability toensure that the prosthetic valve can be tracked to the native valvesite. It is desirable that such a system also provides a means fordeploying the prosthetic valve at the native valve site in a controlledand precise manner. The present invention addresses this need.

SUMMARY

Preferred embodiments of a system for treating a native valve in a humanheart include a delivery sleeve containing a prosthetic valve whichenters a vessel without the use of a guide sheath. Entry without the useof a guide sheath is achieved by the gradual profile of a step balloon,the tip of which protrudes from the distal end of the delivery sleeveand provides a smooth transition from a guide wire to the deliverysleeve.

The delivery sleeve is comprised of materials which give the cathetersufficient pushability, rigidity, and flexibility to allow an operatorto accurately place the distal end of the catheter at a site where theprosthetic valve is to be deployed. The smooth transition of the stepballoon prevents the loosening of calcification and plaque inside thevessel, and particularly in the area of the aortic arch.

Another advantage of the system is the ability to prepare the site ofthe native valve for implantation of the prosthetic valve. It isadvantageous to dilate the stenotic leaflets prior to implanting theprosthetic valve. The leaflets are dilated as the step balloon isdeflated, passed through the opening between the leaflets, and thenreinflated.

Another advantage of the system is the ability to aid in crossing thesite of the native valve for implantation of the prosthetic valve. Thestep balloon provides a smooth tapered tip that transitions to thesheath for easy crossing of the calcified leaflets.

Yet another advantage of the system is the ability to retract the stepballoon through the prosthetic valve after deployment. The tapered tipmay be deflated and collapsed to facilitate retraction of the balloonthrough the prosthetic valve. This feature advantageously reduces oreliminates the possibility of damaging the prosthetic valve leaflets orsnagging on the valve frame during retraction.

At the site of valve deployment, the delivery sleeve retracts, allowingfull expansion of the step balloon. The distal end of a valve cathetercontains flexible extensions which flex outwardly as the ballooninflates. The prosthetic valve is connected to the flexible extensions,thereby providing improved stability and controllability duringdeployment.

In one aspect, a system for treating a native valve in a human heartcomprises a prosthetic valve, valve catheter and tubular deliverysleeve. The prosthetic valve includes an expandable frame and a valvularstructure. The tubular sleeve is configured for advancement through apatient's vasculature. The tubular sleeve defines a passageway and thevalve catheter is configured for slidable advancement through thepassageway. A releasable engagement mechanism is disposed along a distalend portion of the valve catheter for engaging the prosthetic valve. Anactuation mechanism is disposed along a proximal end portion of thevalve catheter for causing the releasable engagement mechanism torelease the prosthetic valve.

In one variation, the releasable engagement mechanism comprises aplurality of flexible extension arms configured to hold the prostheticvalve during expansion of the prosthetic valve at a treatment site. Thesystem may further comprise at least one suture for securing theprosthetic valve to the flexible extension arms. At least one slidablemember is attached to the actuation mechanism and extends distallytoward the prosthetic valve. The slidable member, such as a wire, isretractable for detaching the suture from the prosthetic valve, therebyreleasing the prosthetic valve from the flexible extension arms.

In another variation, the system may further comprise an expandabletransition member extending from a distal end of the tubular sleeve. Inone variation, the transition member comprises an inflatable balloonhaving a tapered distal end portion. The inflatable balloon ispreferably disposed at least partially within the prosthetic valve suchthat inflation of the inflatable balloon assists in the expansion of theprosthetic valve. When the system includes an inflatable balloon, theexpandable frame of the prosthetic valve may be balloon-expandable orself-expanding. In one variation, an expandable basket may be used inplace of an inflatable balloon for providing a dilator or forfacilitating expansion of the prosthetic valve.

In another variation, a handle assembly may be provided for controllablyretracting the tubular sleeve for exposing the prosthetic valve at thetreatment site. In one embodiment, the handle assembly has a distal endportion attached to the tubular sleeve and a proximal end portionattached to the valve catheter. The handle assembly may utilize a leadscrew of other suitable mechanism for advancing the valve catheter in acontrolled manner and securely holding the relative positions of thevalve catheter and tubular sleeve.

In another aspect, a method of deploying a prosthetic valve within anative valve in a human heart is provided. The method includes providingan elongate valve catheter having a releasable attachment mechanismalong a distal end portion. The prosthetic valve is attachable to thereleasable attachment mechanism. The valve catheter and prosthetic valveare placed in a tubular sleeve. The tubular sleeve, valve catheter andprosthetic valve are advanced as a single unit through a femoral arteryand over an aortic arch until the prosthetic valve is substantiallylocated within the native valve. The delivery sleeve is retractedrelative to the valve catheter to expose the prosthetic valve and anactuation mechanism on a proximal end of the valve catheter is actuatedto release the prosthetic valve from the valve catheter.

In one variation, an inflatable balloon is disposed within theprosthetic valve during advancement of the prosthetic valve. A tapereddistal end portion of the inflatable balloon extends from the tubularsleeve for providing a dilator to facilitate advancement through thepatient's vasculature. In another variation, the inflatable balloon maybe used to dilate the native valve by pushing aside the stenoticleaflets, thereby facilitating insertion of the prosthetic valve intothe native valve. In yet another variation, the inflatable balloon maybe inflated after retracting the tubular sleeve to facilitate expansionand seat the prosthetic valve within the native valve. In yet anothervariation, preferred embodiments of the system allow the tubular sleeveto be advanced relative to the valve catheter after exposing theprosthetic valve. Advancement of the tubular sleeve causes theprosthetic valve to collapse again such that it may be repositioned inthe event that the initial deployment is not desirable. Afterrepositioning the prosthetic valve, the sleeve may be retracted againand the prosthetic valve may then be released from the valve catheter.

In another aspect, a device for treating a human heart comprises aprosthetic valve, a tubular delivery sleeve having a proximal end, alead screw nut coupled to the proximal end of the tubular deliverysleeve, and a valve catheter having a distal end configured forreleasable attachment to the prosthetic valve, wherein the valvecatheter and the prosthetic valve are slidably advanceable through thedelivery sleeve. A lead screw is coupled to the valve catheter. The leadscrew engages the lead screw nut and rotation of the lead screw causesthe valve catheter and the prosthetic valve to advance relative to thedelivery sleeve. In one variation, an inflatable balloon is disposedwithin the prosthetic valve for facilitating expansion of the prostheticvalve within the native valve. The inflatable balloon may have a tapereddistal end portion configured to extend from the tubular deliverysleeve. Accordingly, the inflatable balloon may also be used tofacilitate advancement through the vasculature and to dilate thestenotic leaflets of the native valve. The tubular delivery sleeve ispreferably coated with a hydrophilic coating. In another variation, aplurality of flexible extensions is disposed along the distal end of thevalve catheter, the flexible extension being configured for releasableattachment to the prosthetic valve.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of one preferred embodiment of a delivery systemaccording to the present invention with a distal end cut away and shownin cross section;

FIG. 2 is a side view of a balloon catheter of the delivery system;

FIGS. 3A and 3B are cross sectional and perspective views, respectively,of a balloon of the balloon catheter;

FIG. 4 is a side view illustrating proximal and distal ends of a valvecatheter which forms a portion of the delivery system;

FIG. 5 is a cross sectional view of a multi-shaft lumen of the valvecatheter;

FIGS. 6A and 6B are cross sectional and perspective views, respectively,of a collet of the valve catheter;

FIGS. 7A and 7B are cross sectional and perspective views, respectively,of a puck of the valve catheter;

FIG. 8 is a perspective view of a mop of the valve catheter;

FIG. 9 is a side cross sectional view of a delivery sleeve which forms aportion of the delivery system;

FIG. 10 is a cross sectional view along a main portion of the deliverysleeve;

FIG. 11 is a side cross sectional view of a proximal hub of the deliverysystem;

FIG. 12 is a perspective view of a handle assembly attached to thedelivery system;

FIGS. 13A and 13B are exploded and perspective views, respectively, of adistal plate assembly of the handle assembly;

FIGS. 14A and 14B are exploded and perspective views, respectively, of aproximal plate assembly of the handle assembly;

FIG. 15 is a side view of a lead screw of the handle assembly;

FIG. 16 is a perspective view of an embodiment of the handle assemblyincluding a load cell;

FIG. 17 is a perspective view of another embodiment of a handle assemblyincluding a load cell;

FIG. 18 is a side view of yet another embodiment of a handle assembly;

FIG. 19 is a side view of the delivery system, with the proximal hub anddistal end portion of the delivery system shown in cross section;

FIG. 20 is a cross sectional view of an extension of the mop andcorresponding prosthetic valve portion;

FIG. 21 is a side view of the assembly between the alternative handleassembly of FIG. 18 and the delivery system;

FIGS. 22A and 22B show the delivery system approaching a native valvesite, and pushing away diseased native valve leaflets, respectively;

FIGS. 23A to 23E show a distal end portion of the delivery system duringone preferred method of use for delivering and deploying a prostheticvalve.

FIG. 24 is a side view of an alternative embodiment of the deliverysystem showing a mechanical basket tip.

DETAILED DESCRIPTION

With reference now to FIG. 1, a heart valve delivery system 10 includes,generally, a guide wire 12 and a balloon catheter 14 having aninflatable balloon 18 located along a distal end portion. An expandableprosthetic valve 16 is located over the inflatable balloon. The ballooncatheter 14 also includes an elongate balloon shaft 20, and a support 22at a proximal end thereof. The balloon shaft 20 of the balloon catheter14 is received within a valve catheter 23. As will be described in moredetail below, the valve catheter 23 is configured for releasableengagement with the prosthetic valve 16. The valve catheter 23 isreceived within a tubular delivery sleeve 24, with the balloon 18protruding, at least in part, from a distal end of the delivery sleeve24. A proximal end of the delivery sleeve 24 is mounted to a proximalhub 26. A handle assembly 500, which will be discussed and depicted ingreater detail below, may be attached to the proximal hub 26 of thedelivery sleeve 24 to effectuate controlled advancement of theprosthetic valve 16 relative to the delivery sleeve 24.

With reference to FIG. 2, the balloon catheter 14 is shown in greaterdetail. The balloon catheter 14 is provided with a guidewire shaft 31that defines a guidewire lumen. The support 22 is located along aproximal end of the balloon catheter and includes a main shaft 32 and afluid shaft 34 extending diagonally from the main shaft 32. A stop cock35 is located along the fluid shaft 34. The main shaft 32 and the fluidshaft 34 each include a passageway, and the passageways are incommunication with one another. A Touhy Borst valve 36, such asdescribed in U.S. Pat. No. 6,592,544, the contents of which are fullyincorporated herein by reference, extends proximally from a proximal endof the main shaft 32, and includes a tightening valve 37 at a proximalend thereof. The illustrated balloon shaft 20 is substantially tubeshaped and includes an outer surface 38.

In one preferred construction, the balloon catheter 14 is assembled suchthat the outer surface 38 of the balloon shaft 20 is secured to an innersurface of the main shaft 32 of the support 22. The Touhy Borst valve 36is placed over the proximal end of main shaft 32 and secured thereto bya threaded connection between the two components. A compression valveinside the Touhy Borst valve 36 surrounds the guidewire shaft 31 andseals an inner passageway in the main shaft 32 of the support 22 fromthe atmosphere as the tightening valve 37 is tightened.

With reference to FIGS. 3A and 3B, the inflatable balloon 18 has aproximal end portion 40 and a distal end portion 42 and includes aninner surface 44, an outer surface 46, and a passageway 48longitudinally extending therethrough. When viewed from the proximal endportion 40 to the distal end portion 42, the illustrated embodiment ofthe balloon 18 includes seven regions: a first slender region 50, afirst conical region 52, a main cylindrical region 54, a second conicalregion 56, a secondary cylindrical region 58, a third conical region 60,and a second slender region 62. The balloon 18 is preferably inflated bya fluid, such as saline, and may be formed of any suitable material,such as, for example, nylon. The distal end portion 42 of the balloon 18is preferably shaped to provide a transition member between theguidewire 12 and the relative large diameter delivery sleeve 24 (asshown in FIG. 1), thereby facilitating advancement of the deliverysystem through the patient's vasculature. In preferred embodiments, theballoon 18 also provides a dilator tip, thereby eliminating the need fora separate dilator mechanism. The outer surface of the balloon and thedelivery sleeve are preferably provided with a lubricious coating. Thelubricious coating and the shape of the balloon allow the deliverysystem (including the prosthetic valve) to be advanced throughrelatively narrow and or calcified vasculature in a patient.Accordingly, in one advantageous feature, preferred embodiments of thedelivery system may be used without a guide sheath.

With reference to FIGS. 1 through 3B, one preferred construction of theballoon 18 will now be described in more detail. The inner surface 44 offirst slender portion 50 of the balloon 18 is secured to the outersurface 38 of the balloon shaft 20 at a distal end of the balloon shaft,thus placing the passageway of the balloon shaft 20 in communicationwith the passageway 48 of the balloon 18. The inner surface 44 of thesecond slender portion 62 is secured to an outer surface 64 of theguidewire shaft 31. The connection can be achieved by adhesion or bythermal joining, or both. A soft tip 68 having a passageway 70 extendingtherethrough is secured to the outer surface 64 of the guidewire shaft31 at a distal end thereof, and extends distally from the guidewireshaft 31, the passageway 70 of the soft tip 68 being in communicationwith a passageway 71 of the guidewire shaft 31.

With reference to FIGS. 4 through 8, the assembly and function of thevalve catheter 23 will now be described. As best shown in FIG. 4, thevalve catheter 23 provides a releasable engagement mechanism for holdingand releasing the prosthetic valve 16. In the illustrated embodiment,the valve catheter 23 includes a multi-lumen shaft 72, around a proximalportion of which a stiffener tube 74 is disposed. A collet 76 extendsfrom inside a central lumen of the multi-lumen shaft 72 and is snappedinto a puck 78. The puck 78 is snapped into the mop 80 such that the mopextends distally from the puck. The valve catheter 23 also includes awire tube 82 extending proximally from a proximal end of the multi-lumenshaft 72. The valve catheter 23 carries the prosthetic valve 16 to thenative heart valve site and facilitates deployment of the prostheticvalve 16, as described below.

With reference to the cross-sectional view of FIG. 5, the multi-lumenshaft 72 is preferably cylindrically shaped and includes a central lumen84 longitudinally extending therethrough. Six side lumens 86 extend froma proximal end to a distal end of the multi-lumen shaft 72. In oneembodiment, the multi-lumen shaft is made of a thermoplastic elastomersuch as polyether block amide, known as Pebax®.

With reference to FIGS. 6A and 6B, the collet 76 is generallycylindrically shaped and includes a proximal end 90 and a distal end 92.A central passageway 94 extends through the collet. Near the proximalend 90, openings 96 extend from an outer surface 98 to an inner surface100 of the collet 76. Four longitudinal slots 102 pass from the outersurface 98 to the inner surface 100 along the distal end 92 of thecollet 76, thereby creating four flexible arms 104. The slots 104preferably narrow in width from the distal end 92 to the proximal end90. At the distal end 92 of the collet 76, the outer surface preferablyforms an angled surface 106 to facilitate engagement with the puck 78.An annularly shaped flange 108 is located proximally adjacent to theangled surface 106. Along the circumference of the collet 76, the outersurface 98 includes a shoulder surface 109 which extends perpendicularto the outer surface 98 and faces the distal end 92 of the collet 76.

With reference to FIGS. 7A and 7B, the puck 78 is generally tube shaped,having a central lumen 112 extending longitudinally therethrough from aproximal end 114 to a distal end 116. The central lumen 112 is definedby an inner surface 118 of the puck 78. An outer surface 120 of the puck78 includes an angled portion 122 near the proximal end 114. An annulargroove 123 extends around the outer surface of the puck 78 distallyadjacent the angled portion 122. Near the distal end 116, the outersurface 120 includes a snap ridge 124 extending around the circumferenceof the puck 78. The snap ridge 124 is interrupted by four circularindentations 125 which extend from the outer surface 120. The outersurface also includes an annularly shaped flange 126 extending outwardlywhich defines a shoulder surface 130. Six side lumens 136 extendparallel to the central lumen 112 from the angled portion 122 of theouter surface 120 to the distal end 116 of the puck 78. The side lumens136 are equally spaced around the circumference of the puck 78. Acylindrically shaped opening 138 extends radially from the outer surface120 to the inner surface 118 of the puck 78. A pin 139 is inserted intothe opening 138, situated flush with the outer surface and protrudinginwardly from the inner surface 118 of the puck 78.

With reference to FIG. 8, the mop 80 is generally cylindrical in shapeand includes a proximal end 140, an outer surface 142, an inner surface144, and a passageway 145 extending therethrough. The mop 80 preferablyincludes six elongate extensions 150 configured for engagement with theprosthetic valve. In one preferred embodiment, the extensions 150 havevarying lengths configured for engaging different portions of theprosthetic valve. Each extension preferably includes first and secondopenings 152, 154 near a distal end 156. Near the proximal end 140 ofthe mop 80, four openings 146 extend from the outer surface 142 to theinner surface 144, and are aligned along a circumference of the mop 80.Four slots 148 passing from the outer surface 142 to the inner surface144 extend from the proximal end 140 along the length of the mop 80 andpass between the openings 146. The mop 80 is preferably formed of ashape memory material, such as Nitinol, or any other suitable material.

With continued reference to FIGS. 4 through 8, during assembly of thevalve catheter 23, the puck 78 is snapped into the proximal end 140 ofthe mop 80. The slots 148 allow the proximal end 140 of the mop 80 toflex as the distal end 116 of the puck is inserted into the passageway145 of the mop 80 (see FIGS. 7A and 8). The snap ridge 124 of the puck78 enters the openings 146 of the mop 80, and the slot indentations 125of the puck 78 are aligned with the areas between the openings 146 ofthe mop 80. The proximal end 140 of the mop 80 abuts the shouldersurface 130 of the puck 78. The collet 76 snaps into the puck 78. Moreparticularly, the distal end 92 of the collet 76 passes through theproximal end 114 of the puck 78. The arms 104 of the collet 76 flex topass through the central lumen 112 of the puck 78. The protrusion 138 ofthe puck 78 passes through one of the slots 102 of the collet 76, and ispressed tight as the slot 102 narrows. Once snapped, the flange 108 ofthe collet 76 bears against the distal end 116 of the puck 78, and theshoulder surface 109 of the collet 76 bears against the proximal end 114of the puck 78.

The multi-lumen shaft 72 is placed proximally to the puck 78. Theproximal end 90 of the collet 76, including the openings 96, which maybe filled with an adhesive material in order to ensure a strong bond, isinserted into the central lumen 84 of the multi-lumen shaft 72 such thatthe side lumens 86 of the multi-lumen shaft 72 are aligned with the sidelumens 136 of the puck. The connection between the multi-lumen shaft 72and the collet 76 can be made by thermal or adhesive joining, or both.The stiffener tube 74 is placed over the multi-lumen shaft 72 near theproximal end thereof. The stiffener tube 74 extends over a portion ofthe multi-lumen shaft 72. The wire tube 82 is bonded to the proximal endof the multi-lumen shaft 72 and extends diagonally therefrom.

With reference now to FIGS. 9 and 10, the delivery sleeve 24 preferablyincludes a proximal end 160, a distal end 162, an outer surface 164, aninner surface 166, and a passageway 168 extending longitudinallytherethrough. The delivery sleeve 24 includes a main portion 170 and atip portion 172. The delivery sleeve 24 contains and protects theprosthetic valve during advancement through the patient's vasculature tothe native valve site, as discussed below. The main portion 170 of thedelivery sleeve 24 includes an inner layer 173, over which is located amiddle layer 174, over which is located an outer layer 176. The innerlayer 173 of the main portion 170 of the delivery sleeve 24 ispreferably formed of a material, such as Teflon®, having a lowcoefficient of friction. The middle and outside layers 174, 176 arepreferably formed of Pebax®. At least a portion of the delivery sleevemay be coated with a lubricious material. The delivery sleeve 24 furtherincludes a plurality of wires 178, preferably made of stainless steel,which spiral along the length of the delivery sleeve 10.

The delivery sleeve 24 is preferably formed by an extrusion process. Thewires are initially placed between the middle and outer layers of thedelivery sleeve 24 during the extrusion process. The delivery sleeve 24is then laminated by heat, causing the middle and outer layers to flow.The heat of the lamination process softens the middle and outer layers174, 176, causing the wires 178 to imbed into the middle and outerlayers of the delivery sleeve 24, as shown in FIG. 10. The inner layer173, which is preferably formed of Teflon®, does not flow when heatedduring the lamination process.

In one preferred construction, half of the wires 178 spiral along thelength of the delivery sleeve 24 in a direction opposite that of theother half of the wires 178, such that the wires 178 cross one anotherto form a mesh. The wires 178 can also pass over and under one anotherto form a weave or a braid. The wires 178 extend from the proximal end160 of the delivery sleeve 24 toward the distal end 162 in the mainportion 170 of the delivery sleeve 24. The tip portion 172 of thedelivery sleeve 10 does not contain the wires 105, which are placed inthe main portion 170 of the delivery sleeve 24 to ensure adequatestiffness and pushability.

The tip portion 172 of the delivery sleeve 12 is preferably made of softmaterial such as Pebax®. The wires 178 and the inner layer 172 areabsent at the tip portion 172 of the delivery sleeve 24. The tip portion172 is configured such that the passageway 168 is the same size in thetip portion 172 of the delivery sleeve 24 as it is in the main portion170 of the delivery sleeve 24. Approaching the distal end 162 of thedelivery sleeve, and in the tip portion 172 of the delivery sleeve 24,the outer surface 164 tapers, forming a tapered outer surface 180, whichaids in the introduction and tracking of the delivery system 10 in thebody vessel, as described below.

At the transition between the main portion 170 and the tip portion 172of the delivery sleeve, a radiopaque band 182 is disposed between thestainless steel wires 178 and outer layer 176 of the delivery sleeve 24.During the heat lamination process described above, the radiopaque band182 does not flow. After lamination is complete, the radiopaque band 182remains surrounding the ends of the wires 178 and thus serves as abarrier between the outer layer 176 and the wires 178. The radiopaqueband 182 can comprise any suitable material, but is preferably made ofan alloy comprising 90 percent platinum and 10 percent iridium (PLIR).

With reference now to FIG. 11, a cross-sectional view along the proximalhub 26 of the delivery sleeve 24 is provided. The proximal hub 26preferably comprises a cylindrically shaped hub body 200 having apassageway 201 extending longitudinally therethrough. The hub body 200is partially surrounded by a housing 202 located at a distal end of thehub body 200. An end piece 203 having an opening 204 extending into thepassageway 201 of the hub body 200 is mounted to a proximal end of thehub body 200 and protrudes therefrom. An outer surface of the end piece203 includes, when viewed from a proximal end to a distal end, a taperedsurface 205A, a first neck surface 205B, a first shoulder surface 205Cfacing distally, a second neck surface 205D, and a second shouldersurface 205E facing proximally. The first shoulder surface 205C, thesecond neck surface 205D, and the second shoulder surface 205E define agroove 206 extending around the end piece 203.

Proximally adjacent the end piece 203 and inside the hub body 200, across cut valve 207 is located, and is partially surrounded by a spacer208. Proximally adjacent the cross cut valve 206 and spacer 208 andinside the hub body 200, a disc valve 210 is located. A duck bill valve212 is also located inside the hub body 200, proximally adjacent to thedisc valve 210. A hemostasis opening 212 extends from the passageway201, and a hemostasis tube 214 extends from the hub body 200 to athree-way stopcock 216. One preferred embodiment of the proximal hub isdescribed in greater detail in U.S. Pat. No. 5,968,068 entitledENDOVASCULAR DELIVERY SYSTEM, the contents of which are fullyincorporated herein by reference.

With continued reference to FIG. 11, the delivery sleeve 24 is securedto the proximal hub 26. The proximal end 160 of the delivery sleeve 24is inserted into the passageway 201 of the proximal hub 26 at a distalend thereof. The outer surface 164 of the delivery sleeve 24 is securedto an inner surface of the housing 202 of the proximal hub 26 by anadhesive or thermal joining, thus placing the passageway 201 of theproximal hub in communication with the passageway 168 of the deliverysleeve 24.

With reference now to FIG. 12 through 15, one preferred embodiment ofthe handle assembly 500 will be described. The illustrated handleassembly 500 provides a mechanical actuation mechanism for advancing theprosthetic valve from the distal end of the delivery sleeve 24 in acontrolled and precise manner. The handle assembly 500 includes,generally, a distal plate assembly 502 coupled to the proximal hub 26 onthe proximal end of the delivery sleeve 24. The handle assembly alsoincludes a proximal plate assembly 504 coupled to the valve catheter 23.A lead screw 506 passes through the distal and proximal plate assemblies502, 504.

With particular reference to FIGS. 13A and 13B, the distal plateassembly 502 includes a main portion 510, an upper portion 512, and alead screw nut 514. The main and upper portions 510, 512 combine toinclude a first opening 516 passing through from a proximal face 518 toa distal face 520 of the distal plate assembly 502. The first opening516 is defined by a proximal opening surface 522, a distal openingsurface 524, and a shoulder surface 525. The proximal and distal openingsurfaces 522, 524 extend perpendicularly from the proximal and distalfaces 518, 520 of the distal plate assembly 502. The shoulder surface525 faces proximally and extends between the proximal and distal openingsurfaces 522, 524, substantially parallel to the proximal and distalfaces 518, 520 of the distal plate assembly 502. A second opening 526 inthe distal plate assembly 502 extends from the proximal face 518 to thedistal face 520. Fastener openings 527 likewise extending through thedistal plate assembly 502 are located in the area of the second opening526.

The lead screw nut 514 is tube shaped, having an outer surface 528, aninner surface 530, and an opening 532 extending longitudinallytherethrough. An outwardly extending flange 534 extends outwardlyadjacent a proximal end 536 of the lead screw nut 514. Fastener openings538 pass through the flange 534 to the proximal end 536 of the leadscrew nut 514. The inner surface 530 of the lead screw nut 514 isthreaded.

The upper portion 512 of the distal plate assembly 502 is secured to themain portion 510 of the distal plate assembly 502 by distal plateassembly fasteners 540, which engage distal plate assembly fastenerholes 542. The distal plate assembly fastener holes 542 pass through theupper portion 512 of the distal plate assembly 502 and into the mainportion 510 of the distal plate assembly 502.

The lead screw nut 514 is secured to the main portion 510 of the distalplate assembly 502 as the proximal end 536 of the lead screw nut 514 isplaced against the distal face 520 of the main portion 510, and fasteneropenings 527 of the main portion 510 are aligned with the fasteneropenings 538 of the lead screw nut 514. The opening 532 in the leadscrew nut 514 is aligned with the second opening 526 of the distal plateassembly 502. Lead screw nut fasteners 544 engage the fastener openings527, 538 and secure the lead screw nut 514 to the main portion 510 ofthe distal plate assembly 502.

With reference to FIGS. 14A and 14B, the proximal plate assembly 504includes a main portion 546, a cap portion 548, and a handle 550extending from the main portion 546. The main portion 546 and capportion 548 combine to create a central opening 552 passing through froma proximal face 554 to a distal face 556. The central opening 552 isdefined by a proximal opening surface 558, a distal opening surface 560,and an inner cavity surface 562. The proximal and distal openingsurfaces 558, 560 extend perpendicularly from the proximal and distalfaces 554, 556 of the proximal plate assembly 504. The inner cavitysurface 562 runs between the proximal and distal opening surfaces 558,560, and creates an open cavity within the assembled proximal plateassembly 504.

A first side opening 564 in the proximal plate assembly 504 extends fromthe proximal face 554 to the distal face 556. The handle 550 is securedto the main portion 546 of the proximal plate assembly 504 such that itpasses through the first side opening 564 and is secured by a set screw565. A second side opening 566 in the proximal plate assembly 504 alsoextends from the proximal face 554 to the distal face 556. The capportion 548 of the proximal plate assembly 504 is secured to the mainportion 546 of the proximal plate assembly 504 by proximal plateassembly fasteners 568, which engage proximal plate assembly fastenerholes 570. The proximal plate assembly fastener holes 570 pass throughthe cap portion 548 of the proximal plate assembly 504 and into the mainportion 546 of the proximal plate assembly 504.

With reference to FIG. 15, the lead screw 506 includes a rotator knob572 at a proximal end thereof, a non-threaded portion 574, and athreaded portion 576 adjacent a distal end thereof. The rotator knob 572includes a neck portion 578 extending distally therefrom and from whichthe non-threaded portion 574 extends distally. A shoulder surface 580 ata distal end of the neck portion 578 of the rotator knob 572 facesdistally. A groove 581 extends circumferentially around the lead screw506.

With reference again to FIGS. 12 through 15, the handle assembly 500 isassembled as the lead screw 506 is placed through the second sideopening 566 and lead screw nut opening 532 of the proximal plateassembly 504 and the second opening 526 of the distal plate assembly 502such that the shoulder surface 580 of the rotator knob 572 abuts theproximal face 554 of the proximal plate assembly 504. A snap ring 582 isplaced in the groove 581 on the non-threaded portion 574 of the leadscrew 506 such that it abuts the distal face 556 of the proximal plateassembly 504. The snap ring 582 on the distal face 556 and the shouldersurface 580 on the proximal face 554 prevent translational movement ofthe lead screw 514 through the second side opening 556 of the proximalplate assembly 504. The lead screw 506 rotates in the second sideopening 556 of the proximal plate assembly 504. The threaded portion 576of the lead screw 506 engages the threaded inner surface 530 of the leadscrew nut 514.

With reference to FIG. 16, an alternative embodiment of the handleassembly 500 is shown wherein the lead screw nut 514 is locatedproximally from the distal plate assembly 502. A middle plate 590surrounds the lead screw nut 514, and lead screw nut fasteners 544secure the middle plate 590 to the lead screw nut 514. The middle plate590 is secured to a load cell 592, which is secured to the distal plateassembly 502. The load cell 592 as shown in FIG. 16 is known in the art,and may be connected as known in the art to a device (not shown) whichmeasures the displacement on the load cell 592. The device converts thedisplacement of the load cell 592 to the force being exerted to move thedistal plate assembly 502 relative to the middle plate 590.

With reference to FIG. 17, another alternative embodiment of the handleassembly 500 includes a forked portion 594 of the middle plate 590extending toward the handle 550, which passes through an opening 596 ofthe forked portion 594. A second handle 598 passes through the distalplate assembly 502, and is secured by a second set screw 600, whichpasses through the distal plate assembly 502 to contact the secondhandle 598. A handle opening 602 in the distal assembly plate 502 allowsthe handle 550, secured to the proximal plate assembly 504, to passthrough the distal plate assembly 502 unimpeded.

With reference to FIG. 18, another alternative handle assembly 608 isillustrated wherein the proximal and distal plate assemblies are notrequired. A hollow shaft 610 includes snap members 612 extendingparallel thereto. The snap members 612 are connected to the shaft 610 bybridges 614 extending between the shaft 610 and the snap members 612. Ata distal end, the snap members 612 include flanges 616 extendinginwardly toward the shaft 610, forming proximally facing surfaces 618. Adeployment knob 620 having an inner threaded surface is rotatablycoupled to the shaft 610.

With reference now to FIG. 19, the functionality of the delivery system10 will be described in more detail. The balloon catheter 14 isconfigured for insertion into the valve catheter 23. The balloon shaft20 is placed in the central lumen 84 of the multi-lumen shaft 72 and theouter surface 38 of the balloon shaft 20 is secured to an inner surfaceof the multi-lumen shaft 72, such as, for example, by adhesion. Theballoon shaft 20 extends from the support 22, located proximal to theproximal end of the multi-lumen shaft 72, through the central lumen 84of the multi-lumen shaft 72, through the passageway 94 of the collet 76,through the central lumen 112 of the puck 78, to the passageway 145 ofthe mop 80. The main cylindrical portion 54 of the balloon 18 extendsdistally from the distal end 156 of the mop 80. The prosthetic valve 16is crimped sufficiently small to enter into the passageway 168 of thedelivery sleeve 24. The prosthetic valve 16 is supported by the maincylindrical portion 54 of the balloon 18 and is placed against the innersurface 166 of the delivery sleeve 24 in the area of the tip portion172, where it is contained while tracking to the native valve site.

The delivery system 10 is preferably configured for use with aself-expanding prosthetic valve 16. In one preferred embodiment, theprosthetic valve is formed, at least in part, of a memory material, suchas Nitinol, wherein the prosthetic valve takes a rigid shape at apredetermined temperature, but is more malleable at lower temperatures.An example of such a self-expanding prosthetic valve is described inmore detail in U.S. Patent Publication No. 2004/0186563 A1, publishedSep. 23, 2004, the contents of which are fully incorporated herein byreference. It will be appreciated however, that many features of thepresent invention may also be used with other types of prostheticvalves, such as, for example, balloon expandable valves. Examples ofpreferred balloon expandable prosthetic valves are disclosed in U.S.Pat. No. 6,730,118 entitled IMPLANTABLE PROSTHETIC VALVE and U.S. Pat.No. 6,893,460, also entitled IMPLANTABLE PROSTHETIC VALVE, both of whichare fully incorporated herein by reference.

With continued reference to FIG. 19, the delivery sleeve 24 and proximalhub 26 are placed over the valve catheter 23. The valve catheter 23passes through the opening 204 of the end piece 203, the passageway 201of the proximal hub 26 (including valves 207, 210, and 212), and thepassageway 168 of the delivery sleeve 24 (see FIG. 11). The proximal hub26 is located near the proximal end of the valve catheter 23, with thestiffener tube 74 entering the passageway 201 of the proximal hub 26(see FIG. 11) and extending proximally therefrom. The prosthetic valve16 is located in the passageway 168 near the distal end 162 of thedelivery sleeve 24 (see FIG. 11). The self-expanding prosthetic valve 16can be crimped to fit inside a delivery device when subject totemperatures lower than body temperature. The balloon 18 protrudesdistally from the distal end 162 of the delivery sleeve 24.

The guide wire 12 is inserted into the passageway 71 of the guidewireshaft 31. The guide wire 12 extends distally from the distal end of theguidewire shaft 31 and from the soft tip 68, and proximally from aproximal end of the guidewire shaft 31.

A bonded wire 234 extends through the wire tube 82. The bonded wireforms a portion of a preferred actuation mechanism for releasing theprosthetic valve from the valve catheter at the treatment site. Thebonded wire 234 is formed from six individual wires which exit the wiretube 82 at a distal end thereof and enter the six side lumens 86 of themulti-lumen shaft 72. A knob 236 sits on a proximal end of the bondedwire 234. The six individual wires of the bonded wire 234 exit thedistal end of the multi-lumen shaft and enter the side lumens 136 of thepuck 78 (see FIGS. 7A and 7B). The six individual wires of the bondedwire 234 exit the side lumens 136 at the distal end 116 of the puck 78and extend toward the distal end 156 of the mop 80.

Heat shrink 237 can be used to reinforce the connection between themulti-lumen shaft 72, the wire tube 82, and the balloon catheter 14. Theheat shrink 237 is placed over the wire tube 82, the multi-lumen shaft72, and the main shaft 32 of the support 22, and is heat treated untilit forms a hardened shell around the components, thus securing them toone another and making the delivery system 10 more robust.

With reference now to FIG. 20, one preferred means for releasablyattaching the prosthetic valve 16 to the valve catheter will bedescribed. In general terms, the prosthetic valve 16 is preferablyattached to the mop 80 portion of the valve catheter (see FIG. 8) by aflexible elongate member to provide a tether and snare mechanism. Toaccomplish this, one or more sutures 238 (tethers) are passed throughportions of the prosthetic valve and through the mop 80 portion of thevalve catheter. The sutures 238 preferably include loops that extendthrough portions of the prosthetic valve. Slidable wire(s) 234 extendthrough the loops to prevent the suture from detaching from theprosthetic valve. Therefore, the slidable wire(s) 234 provide areleasable snare mechanism that can be withdrawn for quickly and easilydetaching the sutures from the prosthetic valve.

In the preferred embodiment illustrated in FIG. 20, proximal endportions of the prosthetic valve 16 are placed near the second openings154 on the inner surface 144 of the mop 80. The six individual wires ofthe wire 234 extend from the side lumens 136 of the puck 78 (see FIG.7A) and are pressed against the inner surface 144 of the extensions 150of the mop 80. The individual wires pass along the sides of theprosthetic valve 16, with the prosthetic valve 16 placed between theinner surface 144 of the mop 80 and the individual wires. Distal ends ofthe individual wires can be tucked into a commissure pocket of theprosthetic valve 16 or between leaflets at a commissure post of theprosthetic valve 16 to avoid exposure to the delivery sleeve 24 whiletracking and to the body vessel during valve deployment.

An anchor, such as a ring formed of suture or other material, ispreferably provided in the annular groove 123 of the puck 78 (see FIG.7A). The suture 238 is tied into the anchor, and then passes therefromalong the outer surface 142 of the mop 80 (see also FIG. 8), whereuponit passes through the first opening 152 of one of the extensions 150 ofthe mop 80, wraps around the individual wire of the wire 234, andreturns to the outer surface 142 of the mop 80 through the first opening152. The suture 238 then passes through the second opening 154 of one ofthe extensions 150 of the mop 80, through an attachment opening 239 ofthe prosthetic valve 16, around the individual wire 234, returns throughthe attachment point of the prosthetic valve 16, and returns through thesecond opening 154 of the same extension 150 to the outer surface 142 ofthe mop 80. The suture 238 is tied into the anchor at the annular groove123 of the puck 78 such that it forms a suture loop extending from theanchor to the distal end 156 of the extension 150 of the mop 80 (seealso FIG. 8). The suture 238 is used to form a similar suture loopcorresponding to each extension 150 of the mop 80, with a tether orsnare formed near the distal end 156 of each extension 150 of the mop80. The suture 238 is wrapped around itself and tied into a positionaligned with each extension 150 of the mop before passing along theouter surface 142 of each extension 150 to form the suture loop.

With reference again to FIGS. 12 through 18, attachment of the handleassembly 500 to the delivery system 10 will now be described in moredetail. The proximal plate assembly 504 clenches the valve catheter 23,which is inserted into the central opening 552 of the proximal plateassembly 504. The stiffener tube 74 (see FIG. 4) of the valve catheter23 contacts the proximal and distal opening surfaces 558, 560 of theproximal plate assembly 504 (see FIG. 14A). The contact is sufficientlytight to secure the valve catheter 23 to the proximal plate assembly504.

The distal plate assembly 502 is secured to the proximal hub 26. The endpiece 203 passes through the first opening 516 of the distal plateassembly 502 (see FIG. 13B), with the distal plate assembly 502 engagingthe groove 506 of the end piece 203 (see FIG. 11). The first necksurface 205B of the end piece 203 (see FIG. 11) bears against theproximal opening surface 522 of the distal plate assembly 502 (see FIGS.13A and 13B). The first shoulder surface 205C of the end piece 203 (seeFIG. 11) bears against the shoulder surface 525 of the distal plateassembly 502 (see FIGS. 13A and 13B). The second neck surface 205D ofthe end piece 203 (see FIG. 11) bears against the distal opening surface524 of the distal plate assembly 502 (see FIGS. 13A and 13B). The secondshoulder surface 205E of the end piece 203 (see FIG. 11) bears againstthe distal face 520 of the distal plate assembly 502 (see FIGS. 13A and13B).

The embodiments shown in FIGS. 16 and 17 are well-suited for allowingthe operator to be aware of the force being exerted on the prostheticvalve 16 while it is exiting the delivery sleeve 24, described below.The embodiment shown in FIG. 17 is suited to stabilize the handleassembly 500, as the extended distal plate assembly 502 and secondhandle 598 cause an even distribution of weight about an axis defined bythe valve catheter 23. The forked portion 594, in addition to serving asa means to evenly distribute weight about the axis defined by the valvecatheter 23, serves to prevent the device from rotating under thestresses present during valve deployment and operation of the lead screw506, described below.

In the alternative embodiment shown in FIG. 18, the handle assembly 608is attached to the delivery system 10 by snapping the shaft 610 into theproximal hub 26 (see FIG. 11), as shown in FIG. 21. The shaft 610 entersthe opening 204 of the end piece 203 (see FIG. 11). The flanges 616 ofthe snap members 612 pass over the tapered surface 205A and the firstneck surface 205B to engage the groove 206 (see FIG. 11) of the endpiece 203. The proximally facing surfaces 618 of the snap members 612bear against the first shoulder surface 205C of the end piece 203 of theproximal hub 26. The inner threaded surface of the deployment knobengages a threaded surface 622 of the valve catheter 23. The threadedsurface 622 of the valve catheter 23 can be incorporated into thestiffener tube 74 (see FIG. 4)

With reference now to FIGS. 1 through 11, preferred methods of using thedelivery system 10 to deliver a prosthetic valve 16 will be described inmore detail. The guide wire 12 is first inserted into a body vessel,such as the femoral artery, according to methods that are known in theart. The guide wire 12 passes through the arteries of the patient, andthrough an opening in the native valve. If desired, a dilator may beinserted over the guide wire 12 into the body cavity. One preferreddilator is described in more detail in U.S. Pat. No. 5,968,068 entitledENDOVASCULAR DELIVERY SYSTEM, the contents of which are fullyincorporated herein by reference. The dilator acts to enlarge theopening of the body vessel and thereby facilitate the passing of thedelivery system 10 into the body vessel. After vessel dilation and entryof the delivery system 10 into the body vessel, the dilator is removed.However, as discussed above, embodiments of the delivery system 10 maybe used without a dilator due to the shape and coating of the balloonand delivery sleeve.

The delivery system 10 travels over the guide wire 12 and is introducedinto the body vessel. A hydrophilic coating is preferably used toprovide lubricity on the outer surface 46 of the balloon 18 (see FIG.3A) and on the outer surface 164 of the delivery sleeve 24 (see FIG.11). A lubricious surface allows for easier introduction of the device,as well as easier tracking of the device to the site of the nativevalve, by decreasing the amount of friction between the walls of thebody vessel through which the device is tracked. The outer surface 46 ofthe second cone portion 56 of the balloon 18 (see FIGS. 3A and 3B)provides a tapered surface for ease of entry into the body vessel. Atthe distal end 162 of the delivery sleeve 24, the tapered surface 180 ofthe tip portion 172 of the delivery sleeve 24 (see FIG. 9) alsofacilitates entry into the body vessel.

With reference now to FIG. 22A, the delivery system 10 passes over theguide wire 12 as it tracks to a native valve site 250. Tracking occursas the operator pushes the delivery system 10 through the femoralartery, over the aortic arch 254, and to the native valve site 250 in aretrograde (i.e., against the blood flow) procedure. The balloon 18 maybe used to act as a dilator within the body vessel during tracking. Thebody vessel may be constrictive due to size or calcification. Theballoon 18 provides a tapered, soft surface, for gradual dilation ofconstrictive areas of the body vessel as the distal end of the deliverysystem 10 advances therethrough. If necessary, the balloon may bepartially or entirely deflated and then re-inflated during advancementto further facilitate advancement through narrow vasculature. Thestructure of the delivery sleeve 24 gives it sufficient flexibility andpushability to track to the native valve site 250. Fluoroscopy, whereinthe position of the radiopaque band 182 of the delivery sleeve 24 (seeFIG. 9) can be seen relative the native valve site 250, allows theoperator to be aware of the position of the delivery system 10.

During tracking of the delivery system 10 to the native valve site, thedelivery sleeve 24 bends in order to pass through the curves of the bodyvessels, including the curve found in the aortic arch 254. The bendingof the delivery sleeve 24 may cause the components of the valve catheter23 to move relative to the inner surface 166 of the delivery sleeve 24(see FIG. 9). The bending may also cause the passageway of the deliverysleeve 24 to narrow, thereby increasing friction. Accordingly, preferredembodiments of the delivery sleeve 24 have an inner surface 166 formedor coated with a material having a low coefficient of friction such asTeflon®.

As the delivery sleeve 24 bends while tracking to the native valve site250, a bending force is exerted on the wires 178 (see FIG. 10). Theforce on the wires 178 may cause the wires 178 to press against themiddle and outer layers 174 and 176 of the delivery sleeve 24.Accordingly, the radiopaque band 182 (see FIG. 9) is preferably formedfrom material that is sufficiently puncture resistant such that forcesexerted by the ends of the wires 178 cannot puncture the outer layer 176of the delivery sleeve 24 when the sleeve 24 is bending. The inner layer173 of the delivery sleeve 24 (see FIG. 10) also provides protection tothe valve catheter 23 and balloon catheter 14 from the wires 178. Thematerial chosen for the inner layer 173 does not flow under the heatlaminating process described above. The wires 178 do not become imbeddedin the inner layer 173. The inner layer 173 thus provides a barrierbetween the wires 178 and the passageway 168 of the delivery sleeve 24.

With reference to FIG. 22B, once the delivery system 10 has arrived atthe valve site, the operator can push the prosthetic valve 16 (seeFIG. 1) across native valve leaflets 256, thus loosening the leaflets256 that have become stenotic. Aortic stenosis is a disease of theaortic valve of the heart. Stenotic leaflets are thickened, hardened,and calcified; their movement is more limited than healthy leaflets.Stenotic leaflets inhibit blood flow, leaving only a small hole fromwhich blood can be ejected into the aorta. Valve implantation canrequire that the leaflets be removed or pushed out of the way. However,the hardened nature of stenotic leaflets can complicate the looseningprocess.

The balloon 18 is capable of stiffening when inflated and can be used todilate stenotic leaflets of a native heart valve. The balloon 18 isdeflated and the second cone portion 56 of the balloon 18 is passedthrough a small opening between the stenotic leaflets. The balloon 18 isthen reinflated, as shown in FIG. 22B, and the expanding balloon exertssufficient pressure on the hardened tissue of the stenotic leaflets todilate the leaflets. This dilation aids in the deployment of theprosthetic valve 16 (see FIG. 19), described below.

In a preferred method of valve deployment, the delivery sleeve 24retracts as the valve catheter 23 is held steady, exposing theprosthetic valve 16 to an implantation site without requiring that theprosthetic valve track through the body cavity while exposed thereto.Further, there is no need to track the valve through a guide orintroducer sheath, as it remains stationary with respect to the deliverysleeve 24 during introduction into the body vessel and during trackingtherethrough.

In the embodiment shown in FIGS. 12, 16, and 17, wherein the handleassembly 500 is employed, the operator turns the rotator knob 572 toretract the delivery sleeve and thereby expose the prosthetic valve tothe body vessel and effect deployment. The threading of the threadedportion 576 of the lead screw 506 acts on the internal threading of thelead screw nut 514, causing the lead screw nut 514 and the distal plateassembly 502 to translate toward the proximal plate assembly 504, whichis held translationally stationary relative to the lead screw 506 by thesnap rings 582. Thus, the distal and proximal plate assemblies 502, 504move relative to each other, which causes the delivery sleeve 24, whichis attached to the distal plate assembly 502 at the end piece 203 of theproximal hub 26, and the valve catheter 23, which is secured to theproximal plate assembly 504, to move relative to each other.

In the alternative embodiment shown in FIGS. 18 and 21 employing thealternative handle assembly 608, the operator turns the deployment knob620 such that the knob 620, as well as the proximal hub 26 and deliverysleeve 24, which are connected to the deployment knob 620, travelsproximally over the valve catheter 23.

The use of the lead screw 506 or the alternative handle assembly 608potentially reduces the force needed to retract the delivery sleeve fromthe prosthetic valve 16. One complete revolution of the lead screw 506advances the lead screw nut 514 the distance between the individualthreads on the threaded portion 576 of the lead screw 506. The distancebetween threads, known as the pitch, determines the amount of forcerequired by the operator to actuate the rotator knob 572. The smallerthe pitch, the less the translational movement is achieved perrevolution of the rotator knob 572. Less relative translational movementof the delivery sleeve 24 on one hand and the prosthetic valve and valvecatheter 19 on the other hand, the less force required by the systemoperator. In a preferred embodiment of the present invention, the leadscrew has a pitch of ¼ inch.

In an alternative embodiment of the present invention not employing alead screw, the operator holds the valve catheter 23 steady and pullsback (proximally) on the proximal hub 26, which remains outside the bodyvessel, to expose the prosthetic valve to the body vessel and effectuatevalve deployment.

With reference now to FIG. 23A, the delivery sleeve 24 is illustrated inthe retracted position such that the prosthetic valve 16 and theextensions 150 of the mop 80 are exposed. The tip portion 172 of thedelivery sleeve 24 is sufficiently flexible to allow retraction of thedelivery sleeve 24 during valve deployment despite the pressure exertedon the delivery sleeve 24 by the expanding prosthetic valve. In orderfor the retraction of the delivery sleeve 24 to be more easily executedby the operator, the inner layer 173 of the delivery sleeve 24 (see FIG.9) may be formed of a material with a low coefficient of friction, suchas Teflon®.

With reference to FIG. 23B, the balloon 18 can be deflated while theself-expanding capabilities of the prosthetic valve 16 cause it toexpand outwardly. The extensions 15 of the mop 80 are preferablysufficiently flexible such that the extensions may allow expansion ofthe valve while maintaining the connection with the valve 16. Withreference to FIG. 23C, after the prosthetic valve 16 has initiallyexpanded, the balloon 18 may be inflated again to further increase thediameter of the prosthetic valve 16. The additional expansion ensuresthat the prosthetic valve assumes a fully expanded condition whereby thevalve is securely seated at the site of the native valve 250. Duringexpansion of the prosthetic valve, the leaflets 256 at the native valvesite 250 are pressed against the wall of the aorta. As discussed above,the balloon 18 is inflated by a fluid source attached to the fluid shaft34 of the support 22 of the balloon catheter 14 (see FIG. 2). The stopcock 35 controls the flow of fluid into the main shaft 32 and theballoon shaft 20 of the balloon catheter 14 (see FIG. 2). Thecompression valve of the Touhy Borst valve 36 prevents fluid leakagefrom the balloon catheter 14 (see FIG. 2).

The extensions 150 of the mop 80 flex outwardly to accommodate expansionof the prosthetic valve 16. During expansion of the prosthetic valve 16as shown in FIGS. 23B and 23C, the operator can adjust the position ofthe prosthetic valve by advancing or retracting the valve catheter 23 ofthe delivery system 10. The extensions 150 of the mop 80 possesssufficient stiffness to allow the position of the prosthetic valve 16 tobe manipulated with a minimum amount of control. Prior to valvedeployment, control of valve positioning is achieved by the operatorpushing, pulling, or twisting the valve catheter 23. The connectionbetween the valve catheter 23 and the balloon catheter 14 allows formovement of the valve catheter 23 to be transmitted from the valvecatheter 23 to the balloon catheter 14.

With reference to FIG. 23D, it is to be understood that the relativemovement between the valve catheter 23 and the delivery sleeve 24 duringvalve deployment can be reversed, by reversing the direction of rotatorknob 572 (or deployment knob 620) or by manually pushing (distally) theproximal hub 26 while holding the inner catheter 23 steady. In oneadvantageous feature, the delivery sleeve may be moved (i.e., advanced)relative to the valve catheter after initial deployment to reduce thediameter of the valve if the location and/or orientation of the valve isnot desirable. More particularly, as the distal end 162 of the deliverysleeve 24 advances distally over the extensions 150 of the mop 80, theextensions 150 are pushed inwardly. As the extensions are pushedinwardly, the prosthetic valve is collapsed. Therefore, if the operatoris not satisfied with the initial deployment of the prosthetic valve 16,the operator can collapse and reorient the prosthetic valve 16. As aresult, the delivery system may be used to retract the prosthetic valvepartially or entirely back into the delivery sleeve such that theprosthetic valve can be redeployed or withdrawn altogether.

With reference to FIG. 23E, once the operator is satisfied with theposition in which the prosthetic valve 16 is being seated, theprosthetic valve is detached from the extensions 150 of the mop 80. Todisconnect the prosthetic valve 16 from the valve catheter 23, the pullson the knob 236 connected to the bonded wire 234 (see FIG. 19). Thedistal ends of the six individual wires of the wire 234 are pulled fromthe commissure pockets and valve leaflets and from the suture 238,allowing the suture to exit the attachment point of the prosthetic valve16 and thus freeing the suture 238 from the prosthetic valve 16 (seeFIG. 20). The prosthetic valve 16 is then detached from the valvecatheter 23. Detachment of the prosthetic valve 16 can occur at any timethat the operator deems appropriate, but usually occurs when theextensions 150 have expanded outwardly to their fullest extent.

After releasing the prosthetic valve 16, the valve catheter 23 andballoon catheter 14 are preferably returned to the passageway 168 of thedelivery sleeve 24 (see FIG. 11). To return the valve catheter 23 andballoon catheter 14 to the passageway 168 of the delivery sleeve 24 inthose embodiments of the invention including the handle assemblies 500,608 (see FIGS. 12 and 21), the operator reverses the direction ofrotator knob 572 or deployment knob 620. In the alterative embodimentnot employing a lead screw, the surgeon pulls (proximally) on the valvecatheter 23 and balloon catheter 14 while holding the delivery sleeve 24stationary (see FIG. 1). The delivery system 10 is then withdrawn fromthe body vessel of the patient.

Although preferred embodiments described herein include a ballooncatheter which may be used as a dilator tip and may also be used to helpseat the prosthetic valve, it will be appreciated that the system may beused without a balloon catheter. When no balloon catheter is provided,the prosthetic valve is released from the valve catheter andself-expands with sufficient force to firmly implant itself at thetreatment site. In another variation of the preferred embodimentsdescribed herein, the delivery system may be configured such that theballoon catheter and the valve catheter form an integrated unit.

With reference to FIG. 24, in another alternative embodiment, thetransition member protruding distally from the delivery sleeve 24 maytake the form of a mechanical basket 700 to facilitate entry into thebody vessel and tracking to the native valve site. The mechanical basketincludes struts 702 enveloped in a urethane covering 704, which issecured over the guidewire shaft 31 at a distal end and a basket shaft705 at a proximal end. The struts 702 are formed with laser cut tubing.The struts can be heat set to flex outwardly, and preferably are formedof super elastic Nitinol in order to expand and collapse effectively.The urethane covering 704 provides a smooth rounded tip for trackingthrough the aorta. During tracking, the basket 700 protrudes from thedistal end 162 of the delivery sleeve 24.

The basket shaft 705 passes through the balloon shaft 20. The balloon 18is secured over the basket shaft 705 at the distal end 42 (see FIGS. 3Aand 3B) and to the balloon shaft 20 at a proximal end 40 (see FIGS. 3Aand 3B). The balloon shaft 20 passes through the delivery sleeve 24.

The guidewire shaft 31 protrudes distally from the basket shaft 705 andincludes a pull wire 706 extending from a distal end of the guidewireshaft 31, where it is attached, through the basket, and to the proximalend of the delivery system 10, where it can be operated to expand orcollapse the basket 700. The guidewire shaft 31 and basket shaft 705pass through the delivery system 10 and protrude proximally from thesupport 22 (see FIG. 2). The basket shaft 705 protrudes proximally fromthe guidewire shaft 31. The guidewire shaft 31 and basket shaft 705 canmove relative to each other as the operator holds the basket shaft 705steady and pushes or pulls the guidewire shaft 31. The operator can alsouse the pull wire 706 to achieve relative movement between the guidewireshaft 31 and the basket shaft 705. Relative movement between the shafts31, 705 at a distal end causes the struts 702 of the basket 700 to flexinwardly or outwardly as the distal and proximal end of the basket moveaway from or toward one another.

While tracking to the native valve site, the basket 700 protrudesdistally from the distal end 162 of the delivery sleeve 24. The shape ofthe basket 700 provides a tapered surface for ease of transition intothe body vessel, and for ease of tracking through the body vessel to thenative valve site, similar to the balloon 18, as described above.

In the alternative embodiment shown in FIG. 24, relative movementbetween the guidewire shaft 31 and the basket shaft 705 is used tocollapse and expand the struts 702 of the basket 700. The urethanecovering 704 collapses with the struts 702. The mechanical basket 700can be collapsed and expanded to loosen stenotic leaflets, or dilateconstrictive portions of the body vessel. The prosthetic valve 16 can beplaced on the balloon 18 and in the delivery sleeve 24, as in the otherembodiments discussed herein, and valve deployment can occur similarlyas in the other embodiments discussed herein.

While the invention has been described in its preferred embodiments, itis to be understood that the words which have been used are words ofdescription and not of limitation. Therefore, changes may be made withinthe scope of the appended claims without departing from the true scopeand spirit of the invention.

What is claimed is:
 1. An assembly for treating a native valve in ahuman heart, comprising: a prosthetic heart valve including a proximalend portion, a distal end portion, an expandable frame, and a valvularstructure; a tubular sleeve defining a passageway; a valve catheterdisposed in the sleeve and having a proximal end portion and a distalend portion, the valve catheter and the sleeve configured to be advancedtogether through a body vessel to the heart; a plurality of metalextension arms coupled to the distal end portion of the valve catheterand releasably coupled to the proximal end portion of the prostheticheart valve, wherein the extension arms are configured to hold theprosthetic heart valve, to radially expand with the prosthetic heartvalve during expansion of the prosthetic heart valve at a treatmentsite, and to radially contract when relative movement between the sleeveand the valve catheter results in the extension arms being disposedwithin the sleeve; and a plurality of metal rods extending distally fromthe distal end portion of the valve catheter, wherein the rods arereleasably coupled to the proximal end portion of the prosthetic heartvalve and are axially movable relative to the extension arms.
 2. Theassembly of claim 1, wherein the extension arms are circumferentiallyspaced relative to each other, and wherein each rod is circumferentiallyaligned with a respective extension arm.
 3. The assembly of claim 1,further comprising a plurality of release members coupled to the distalend portion of the valve catheter, wherein each of the release membersis moveable between a first state and a second state, wherein when therelease members are in the first state, each release member extendsthrough a respective aperture of the prosthetic heart valve, therebyreleasably retaining the prosthetic heart valve on the rods and theextension arms, and wherein when the release members are in the secondstate, each release member is removed from its respective aperture,thereby allowing the prosthetic heart valve to be released from the rodsand the extension arms.
 4. The assembly of claim 1, further comprising abase extending into an opening of the distal end portion of the valvecatheter, wherein proximal end portions of the extension arms arecoupled to the base.
 5. The assembly of claim 1, further comprising ahandle portion having an actuation mechanism and a knob, and the sleeveand the valve catheter are adjustably coupled to the actuationmechanism, wherein rotating the knob relative to the valve catheteractuates the actuation mechanism, thereby causing relative axialmovement between the sleeve and the valve catheter.
 6. The assembly ofclaim 5, wherein the actuation mechanism includes a lead screw coupledto the knob.
 7. The assembly of claim 5, wherein the knob of the handleportion is a first knob, and the handle portion further comprises asecond knob, wherein the rods are coupled to the second knob, andmovement of the second knob relative to the valve catheter causes therods to move axially relative to the prosthetic heart valve and theextension arms, wherein the first knob is rotatable relative to thevalve catheter, and the second knob is moveable relative to the valvecatheter.
 8. An assembly for treating a native valve in a human heart,comprising: a prosthetic heart valve including an expandable frame, avalve structure, a first end portion, and a second end portion; and adelivery apparatus, comprising: a valve catheter having a proximal endportion and a distal end portion; a cylindrical coupling elementconnected to the distal end portion of the valve catheter; and aplurality of elongate, metal extension arms having first and second endportions, wherein the first end portions of the extension arms arecoupled to the coupling element, and wherein the second end portion ofeach of the extension arms is releasably coupled to the prosthetic heartvalve and has a rectangular cross-sectional profile in a planeperpendicular to a longitudinal axis of the extension arm.
 9. Theassembly of claim 8, wherein the second end portions of the extensionarms include openings formed therein that are configured for releasablycoupling the extension arms to the prosthetic heart valve.
 10. Theassembly of claim 9, further comprising a plurality of release memberscoupled to the distal end portion of the valve catheter, wherein thefirst end portion of the prosthetic heart valve has a plurality ofapertures formed therein, wherein each of the release members extendsthrough a respective aperture of the prosthetic heart valve and througha respective opening of the extension arms.
 11. The assembly of claim 8,wherein the extension arms are circumferentially spaced relative to eachother.
 12. The assembly of claim 8, wherein the coupling element has aproximal end portion, a distal end portion, and a lumen extending fromthe proximal end portion to the distal end portion.
 13. The assembly ofclaim 12, wherein the proximal end portion of the coupling element hasan annular flange that extends into the distal end portion of the valvecatheter.
 14. The assembly of claim 8, wherein the coupling element hasa first portion and a second portion disposed distally from the firstportion, wherein the first portion has a first diameter, and wherein thesecond portion has a second diameter greater than the first portion. 15.The assembly of claim 8, wherein the extension arms are formed fromnitinol.
 16. An assembly for treating a native valve in a human heart,comprising: a prosthetic heart valve including an expandable frame, avalve structure, a first end portion, and a second end portion; and adelivery apparatus, comprising: a tubular sleeve defining a passageway;a valve catheter disposed in the sleeve and having a proximal endportion and a distal end portion, the valve catheter and the sleeveconfigured to be advanced together through a body vessel to the heart; aplurality of extension arms coupled to the distal end portion of thevalve catheter and releasably coupled to the first end portion of theprosthetic heart valve, wherein the extension arms are configured tohold the prosthetic heart valve; a plurality of rods extending distallyfrom the distal end portion of the valve catheter, wherein the rods arereleasably coupled to the first end portion of the prosthetic heartvalve and are axially movable relative to the extension arms; and ahandle portion having an actuation mechanism and a knob, wherein theactuation mechanism includes a lead screw, wherein the actuationmechanism is coupled to the sleeve and the valve catheter such thatrotating the knob relative to the valve catheter rotates the lead screw,which results in relative axial movement between the sleeve and thevalve catheter.
 17. The assembly of claim 16, wherein the actuationmechanism is configured such that rotating the knob in a first directionmoves the sleeve proximally relative to the extension arms and theprosthetic heart valve and rotating the knob in a second direction movesthe sleeve distally relative to the extension arms and the prostheticheart valve.
 18. The assembly of claim 17, wherein the extension armscomprise a shape memory material and expand radially outwardly whenexposed from the sleeve.
 19. The assembly of claim 16, wherein thedelivery apparatus further comprises a cylindrical coupling elementconnected to the distal end portion of the valve catheter and to theextension arms.
 20. The assembly of claim 19, wherein the couplingelement has a proximal portion, a distal portion, and an intermediateportion disposed between the proximal and distal portions, and whereinthe intermediate portion has a first diameter that is less than a seconddiameter of the distal portion, and when the proximal portion isdisposed within an axial bore of the distal end portion of the valvecatheter.